Battery Maintainer vs Battery Charger
 

I understand that a battery charger does exactly what it's named: charge the battery.

A battery maintainer sort of "conditions" the battery and always keeps it on top shape.

My question is, can I simply buy a battery maintainer and use it as a charger? Or are maintainers too "weak" to actually charge the battery? I'm sort of confused.

I was reading many reviews of the "cheaper" battery chargers, and I don't think I can really trust them. Also I don't have the money to go all out. On top of that, I don't think I can use a charger without blowing up the battery... lol

So what are your opinions?

There is a battery maintainer from snap-on that I am interested in, as the price isn't bad.

Here's the direct link: http://buy1.snapon.com/catalog/item....re&dir=catalog

A good question. I'm looking forward to some replies.

It would work, but it would probably take about 24 hours to fully charge a battery.

Yes, a battery maintainer/tender charges. I wouldn't really say it "conditions" or makes the battery better though, it's just a charger with a brain. It charges until the battery is full, recognizes that, and then stops charging. As long as it's still connnected it can sense when the battery is starting to lose charge from sitting and then automatically starts charging it again.

A friend had a similar charger and found that it wasn't enough to top off his X5.

If I were in your shoes, I'd spend a bit more money and get a charger that is sized to charge and then maintain your battery, for example, this unit which should be fine for the stock battery.

You'll find some more info on that one here.

Yikes, that snapon charger is way overpriced for a 1.5amp charger..

I use a battery tender JR .75amp trickle charger/tender and it works fine. Now, if a battery is completely dead, you may need a more powerful charger to get a charge back into it, but if you are storing a car and need to keep the battery in good shape, you should not need a 1.5amp or higher trickle charger.

It really depends on what's running down the battery. My friend was making a lot of short trips that never gave time to fully recharge the battery. Hence, he needed a faster charger. I bet his old maintenance charger would have been just fine if, instead, the problem was that he had been parking the car for days at a time and having that slowly drain the battery.

Most cars with anti-theft, alarms, and radio memory pre-sets will draw less than 100 milliamps. So a 1-1.5 amp battery maintainer should be enough to keep a good battery fully charged when the car is off or in storage for long period of time. Now when the battery is completely flat, you may be able to revive it but you will have to wait coz it will take more than a day to recharge it.

Sulfation typically starts to degrade an automotive battery when it falls below roughly 80% charged. That suggests it wouldn't hurt to charge/float charge a 60Ah battery experiencing a 50mA quiescent draw if the car will be sitting for more than a week or two (20% x 60Ah / 0.05A = 240 h). Or perhaps less, if the car only sees short trips.